That's true, a little bit of everything can be a good thing but case in hand... a business I have dealt with does business site development and hosting, when talking to them following a fire at the business they told me they had 75% of the sites they hosted back up in 3-4 weeks. I couldn't help but wonder why it took so long, then they told me they only hosted sites on an SDL link in a coms cab at the end of the office, basic UPS and no off site redundancy.... If as a business my site or more importantly email went offline for anything more than a day the impact to my business would be huge let alone 3-4 weeks.
If you want to run a 'mom & pop' ISP (ala US small cable co's rather than as a reseller/VISP) you're going to find it difficult to say the least, the advice given in that thread although at times quite negative was factual, market saturation and low margin's are not the kind of market you get into unless you have a niche premium product or a lot to spend as the COA will be high unless you can convince friends/family to take your product. As one of those who said something along the lines of 'if you have to ask in here you are probably not ready to get into the isp market' please do let us know how you get on, all I can wish you is the best of luck as you will need it.