This forces you out of the market because of the sudden loss, stop being hit, or lack of discipline, etc. Yes, don't use cycles at all, or perhaps use them in conjunction with other sound methods or technicals. There is no question that Seasonals exist in the markets. This is particularly true in Agricultural where seasonals are very well documented. Seasonals also appear in financials, but not as reliable as agricultural.
Seasonals work because of fundamental reasons, frequently tied to the growing season or the weather.
However, it's very hard to make money using seasonal data, regardless of the history of the seasonal tendency. A perfect example of a contra-seasonal move, are major bear markets in the grains occurring a couple times during the past several years. According to extensive and well-documented research going back to the 1800's, the grains should move up during late Spring and early Summer. However, at certain times in the 1990's they trended sharply down, when they should have been trending steadily higher according to the seasonals. Unfortunately, the seasonal experts will be mad about this, but probably the best way to deal with seasonals are to ignore them, especially in markets other than Agricultural markets.