You'll be welcome in plenty of places mate - most flying school managers are quite resigned to the fact that their instructors are looking to build hours and leg it to the airlines. Hence the reason why the pay is so crap.
Besides, you have to build hours even if you want to be a career instructor these days, the decent paying employers (ie OATS and Bae) don't want you until you have 1000 hours or so. So you'll have to grin and bend over for a year or two regardless, before you can reap the fruits of your labours.
There is always a high turnover of instructors in your average PPL flying school for the reasons stated above, and the theory is that it's going to get better for instructing jobs as this JAR thing makes the self improver route ever more costly and difficult. I reckon you'll be OK.