Most counters, myself included, will overbet their BR and go bust somewhere along the line in one or 2 brutal sessions. Guys like Frank just continually bleed themselves dry.... My BR was built up from card counting and poker, then I foolishly bet 10 kellys per in a +6 tc shoe. Lost 10 of 13 hands, tied the other 3, (2 by taking insurance). I think Frank was standing next to me on one of thewm because I'll be damned if i didn't double 11 vs. 9 at about +19 running with $150 in the circle and have an ace drop on me. Plus, many counters do not practice enough to gain a significant edge, again, probably myself included, and will at times get jaded into overbetting by seeing morons splitting 5's versus an 8 with $500 out, getting two stiffs, and having the dealer bust after you hit your 12. Happens to the best of us.
of people comming on here and complaining that either they went broke while card counting or they know others who went broke. There isn't one reputable blackjack book published in the last 25 years that doesn't spend a large amount of time talking about risk of ruin.
Going broke is a FACT OF LIFE in any business venture. More than half of all businesses fail in the first few years for various reasons (chief among them is being under-capitalized). Many other business fail due to a run of dumb bad luck.
Blackjack is a business. In the service industry, being a great chef doesn't mean that he/she knows how to run a successful restaurant. Likewise, there is much much more to being a successful professional gambler than just being able to count cards.