I try to work with each Q&A question and provide all the assistance or discussion I can. I choose not to leave a topic simply because of various challenges which may arise.

I have directly answered your exact question several times, but you seem unsatisfied so I will try again.

how does hyphenating brain-games.com for a site about brain games, constitute spam?

The determination of "spamminess" is made by those in position of power. Neither you nor I have that power. With respect to this conversation, Google and the general public, more specifically people who use search engines, determine spam.

Using your Viagra example, the overwhelming majority of the public would share sites which sell Viagra are spammy. Pfizer can make the greatest product, and I am sure there are sites which sell viagra which are good sites, but I am also certain there is an overwhelming number of sites which sell viagra would be considered spammy by most people. Therefore, people associate "viagra" with spam, whether or not the product itself is good or bad. It is a well-known component of the human condition that people act upon their perceptions irregardless of whether their beliefs are accurate.

In a similar manner, sites with hyphens in the URL have been badly abused in the past and have earned a reputation as spammy. It seems you desire further evidence. The next step would be taking surveys of SEOs and regular searchers to gather feedback. It seems unquestionable that a percentage of people will identify hyphenated URLs as spammy. It also is quite logical the more hyphens in a domain name, the more spammy a site will seem.

Again, for me this is a general discussion. We are just chatting. It seems you do not feel my responses are helpful so I will leave you to your beliefs.

Alt images can use alt text. The ALT parameter is designed to identify contents of an image to those without the ability to see images such as the visually impaired.

Anchor text is the term given to text which can be clicked on to take a user to a given URL.

Frankly, most "link building" services are pure crap. In my experience the overwhelming majority of them offer no value whatsoever. Many do more harm then good.

The most important factor is to ensure only one URL is available for each page. You should not present the same page through both the /index.html and / URLs. Pick one.

My strong preference is to use the simple / URL as "index.html" does not offer any value to users nor search engines. It just makes the URL longer and more cluttered.

I'm sure Google knows that these are the same pages and does not consider them as duplicate ...

Not true. On your site you may choose to offer the same content via /index.html and /, but another site could choose to present completely different content on those pages. You are offering two unique URLs, your content is duplicated and that can cause multiple issues. Duplicate content is an issue and a division of your links is another issue.

The simple fix is to design your site from the beginning to only offer a / page and not a index.html page. If you have an existing site where this is an issue, use the 301 redirect to fix the problem.

Hyphens should be avoided in domain names. If your site is "California-Realty.com" you will definitely lose a percentage of your site's visitors to CaliforniaRealty.com. If you do use a hyphen, do not use more then one or it would be considered spammy.

I have also seen where a weak site in an easy market  will quickly top the list because the hyphenated domain name matches the search term

Ranking for non-competitive phrases does not require any skill. If you have a site "xyzpdq.com" you can create a web page "Humpty Dumpty ranks well in Google". You can make a ton of SEO errors but as long as your page title and header tag matches the above phrase, you are likely to rank as #1 for it.

The entire point of SEO is competition. If you want to rank for something that no one else wants, it's all yours. The challenge is to rank for a phrase for which others want to rank. I checked "fort meyers auto air" and you do indeed rank as #1 for that term. A check of Google AdWords Keyword Tool shows this phrase to be non-competitive with no monthly searches. I would much prefer to rank #5 for a phrase which receives search traffic then #1 for a phrase which receives none. One way in which "bad" SEOs promote themselves is by sharing how many non-competitive keywords for which they were able to rank well.

Additionally, many searchers will look at the site URL before clicking on it. The problem with spammy URLs is even if you manage to rank well, your CTR is reduced which devalues your ranking.

I just wanted to share I completely agree with EGOL and the understanding he shared. I skipped responding to this question because I didn't want to respond with all the explanation of the disclaimers, where EGOL tackled the question anyway and offered great details in both the original reply and follow up.