Post length is an issue that has been troubling me lately. I've always thought that short to medium posts were the way to go: walls of text drive away readers, because most of them 1) don't have time to read and 2) don't know yet if they'll be interested or not.
However, certain topics do require a descrete level of insight. The only compromise you can reach is to make a post summary (or a TL;DR) to put on front to give potential readers a plausible idea of what the article is going to be about and whether or not they'll be interested.
This solution, though, has a glaring downside: why read the whole article when you have everything summed up in a couple of paragraphs? Even the most interested of readers will take the opportunity to save time, if they feel like they won't be missing out on anything significant.
There are ways around it, but, of course, they all require a significant time investment. The obvious solution is to make your articles interesting, to keep your readers engaged with smart writing, but not everyone has this gift (and, depending on the topic, it's also not always possible). Summaries could also be replaced with images and significant quotes, but, of course, this represents a significant limit.

TL;DR: So, should you make summaries for your articles or could it cause the original texts to be overlooked?