Prejudice.

Attitudes vary depending upon the individual club, and seldom do they coincide with logic. Dogmatic opinions on the 4 vs 2 stroke argument are ego driven and emotively based in the same vein as the mode 1 vs mode 2 debates. There are however predominently logical pros and cons you can use to determine whether a 4 or 2 stroke is best for any proposed scenario, though in the end, the decision seldom comes down to anything other than pure desire and a novelty or prejudicial driven preference.

I don't buy the "4 strokes sound more realistic" rationalisation. They sound like a single cylinder model engine period.

In the end, more than anything at this time it still really comes down to your budget, but the theoretical pros and cons are:

Four stroke
Cons
Much more expensive
Relatively fragile
Less powerful per capacity
Much poorer power to weight ratio

Pros
Lower fuel consumption
Can usually be propped quieter (diameter and RPM related)
Torquier per rated power output (not per capacity)

Differences - neither pros nor cons
slower reving
different exhaust note
novelty appeal
exclusivity &/or status appeal eg: YS


Two stroke
Cons
Higher fuel consumption
Noisier when propped for very high rpm or inadequately silenced
Peakier power curve

Pros
Inexpensive
Wider selection
Robust
Powerful for capacity
Excellent power to weight ratio
Fast

Differences - neither pros nor cons
faster reving
different exhaust note
also ran appeal & status

Bottom line is if you want one, get one and try it. You might like it. Ultimately which you choose should ideally comes down to what brings you most enjoyment, what you can afford and which is best suited to the role you have in mind for it.