What it means to paint "well" is completely in the eye of the beholder. Some people value technical proficiency, others emotional impact, yet others conceptual

What it means to paint "well" is completely in the eye of the beholder. Some people value technical proficiency, others emotional impact, yet others conceptual cleverness or originality, etc, etc, etc. Trained artists often value different things in art than the general public, and critics value different things still (and often disagree with other critics). Ultimately it just comes down to personal preference and taste.