Certainly, but you need to be aware that some blogging software is better behaved than others.
There are plenty of phpBB intalls running here without difficulty. Your friend was probably doing something during configuration or the initial "seeding" of the forum that was computationally expensive. Impatience can play a big role in something like that -- you can use a "burst" of high CPU or high memory, but if it's sustained for any length of time, you can trigger an HRU suspension. (One of the things that can do it is uploading large numbers of images to a platform that creates thumbnails and resizes images to a standard size for gallery display. Each process is just a "blip" in the system, but if you put a lot of "blips" together for a long enough time, it looks like one continuous high demand.)
With this in mind, a word of warning about WordPress. While the newest release ("Gershwin") addresses some of the major issues, WordPress just sort of "grew" over the years. The original problems (caused, admittedly, by earlier versions of PHP and MySQL) were never really addressed, and with the addition of features over the years WP became a bit of a resource hog. It takes far more database calls than are necessary to create and serve a page. Some of the plugin modules that add features are written without regard for computational intensity or memory space requirements. WordPress can be tuned to run within the limits of free hosting (using caching, avoiding "expensive" plugins, etc.) but it has also been the source of a significant number of HRU suspensions here. When in doubt, search the web for any reports of performance issues with any plugins you might want to use -- you won't be the only person having them.
So, yes, you can run a blog here. Just be careful with your choices if you want to run WordPress, and try to take it easy during the set-up process (using any software).
