You're comparing a thoroughly tested science (that people's lives depend on) to drawing silly lines on a chart (which has zero evidence of giving you an edge)?
I say no, especially in the modern algo-dominated markets. The burden of proof is on the trend-line believers, though. They need to either
1) Develop and code an objective trendline system that beats the market (using standard industry metrics) in both back and forward-testing or
2) Track the trades of a more subjective trendline-based trader using a 3rd-party auditing service and see how they perform.
Is that you in blue t-short?
OK, hope will change soooon.